Professor John Porrill BA, PhD
The University of Sheffield
Sheffield S10 2TP, UK
Tel: (+44) 0114 222 6557
Fax: (+44) 0114 276 6515
BA, PhD (Cantab)
My research is aimed at developing a computational understanding of the brain and its role in behaviour.
Very fruitful collaborations with psychologists and neuroscientists (my own training is as a mathematician and theoretical physicist) have allowed me to develop a programme of research based on combining rigorous mathematical modelling with a detailed understanding of the underlying neuroscience.
Identifying the cerebellar algorithm
The central theme of my current research is to identify the cerebellar algorithm. With colleagues I have developed a view of cerebellar function which emphasises the importance of a basic 'decorrelation control' algorithm implemented in the repeating microcircuit based around the Purkinje cell.
This research has been more successful than we could have hoped. For example:
- It provides a unified description of sensory and motor functions;
- It has revealed a surprising functional role for closed cerebellar loops which have recently been traced in detail and whose function is regarded as a challenge to theorists;
- It has provided a computational answer to the longstanding puzzle as to why there are two sites of plasticity in VOR adaptation;
- In addition the algorithm has been implemented in hardware by our collaborators in Bristol Robotics Lab and is successfully learning to stabilise a robot mounted camera.
Our enthusiasm for a cross-disciplinary approach makes myself and my close colleague Paul Dean natural partners in current and planned multi-site research programmes linking neuroscience and robotics.
BBSRC, Dean & Porrill Sheffield, lead by UCL with Cambridge: Cerebellum as a neuronal machine: behavioural, electrophysiological and computational analysis of classical conditioning. (2004 for 3yrs) c. £750K
EPSRC, lead by Dean & Porrill, Sheffield with Edinburgh & UWE: Functions of Distributed Plasticity in a Biologically-Inspired Adaptive Control Algorithm: From Electrophysiology to Robotics. (2004for 3yrs) £767K.
BBSRC, Dean & Porrill: Neural Control of Eye Movements (2000 for 3yrs) £120,000
Teaching and administrative duties
I am module organiser for module 336. I am also responsible for U/g admissions and sit on the Psychology Management Committee, Psychology Teaching Committee, Computing Committee and Postgraduate Studies Committee.
Activities and Distinctions
- I was an invited participant in recent workshops on the future of cerebellar research held at the University of Tuebingen & St Louis and co-author of the workshop review in Cerebellum.
- I was an invited participant in the Foresight Cognitive Systems Project InterAction conference organised in 2003 by the DTI and in a number of Cluster Group Meetings supported by the EPSRC in 2004.
- I was elected Fellow of the Institute of Mathematics and its Applications in 2001.
Invited presentations include
- London 2006: invited discussant Gatsby Foundation International conference on the Cerebellum
- Edinburgh 2005, 2006: Neurosciences Graduate Program
- Antwerp 2005: Neuro-IT Cerebellar Modeling Workshop
- Dorchester 2005: Quinetiq Symposium: Learning in Neuronal Networks
- Warwick 2005: Mathematical Neuroscience: network analysis
- Tuebingen 2004: International Conference on the Cerebellum
- Oxford 2004: Symposium on Biological and Computational Vision
- Edinburgh 2003: EPSRC Novel Computation Initiative
- I am currently co-supervising Adrian Haith, a PhD student at the University of Edinburgh in the Neuroinformatics Doctoral Training Centre.
- Dr Nathan Lepora (BBSRC)
- Dr Sean Anderson (EPSRC)
A list of key publications can be found below. For a full list of publications please click here
- Anderson SR, Porrill J, Pearson MJ, Pipe AG, Prescott TJ & Dean P (2012) An internal model architecture for novelty detection: implications for cerebellar and collicular roles in sensory processing.. PLoS One, 7(9), e44560.
- Dean P & Porrill J (2011) Evaluating the adaptive-filter model of the cerebellum.. J Physiol, 589(Pt 14), 3459-3470.
- Dean P & Porrill J (2010) The cerebellum as an adaptive filter: a general model?. Funct Neurol, 25(3), 173-180.
- Anderson SR, Pearson MJ, Pipe A, Prescott T, Dean P & Porrill J (2010) Adaptive cancelation of self-generated sensory signals in a whisking robot. IEEE Transactions on Robotics, 26(6), 1065-1076.
- Menzies JR, Porrill J, Dutia M & Dean P (2010) Synaptic plasticity in medial vestibular nucleus neurons: comparison with computational requirements of VOR adaptation.. PLoS One, 5(10).
- Dean P, Porrill J, Ekerot CF & Jörntell H (2010) The cerebellar microcircuit as an adaptive filter: experimental and computational evidence.. Nat Rev Neurosci, 11(1), 30-43.
- Lenz A, Anderson SR, Pipe AG, Melhuish C, Dean P & Porrill J (2009) Cerebellar-inspired adaptive control of a robot eye actuated by pneumatic artificial muscles.. IEEE Trans Syst Man Cybern B Cybern, 39(6), 1420-1433.
- Porrill J & Dean P (2008) Silent synapses, LTP, and the indirect parallel-fibre pathway: computational consequences of optimal cerebellar noise-processing.. PLoS Comput Biol, 4(5), e1000085.
- Porrill J & Dean P (2007) Cerebellar motor learning: when is cortical plasticity not enough?. PLoS Comput Biol, 3(10), 1935-1950.
- Porrill J & Dean P (2007) Recurrent cerebellar loops simplify adaptive control of redundant and nonlinear motor systems.. Neural Comput, 19(1), 170-193.
- Porrill J, Dean P & Stone JV (2004) Recurrent cerebellar architecture solves the motor-error problem.. Proc Biol Sci, 271(1541), 789-796.
- Dean P, Porrill J & Stone JV (2002) Decorrelation control by the cerebellum achieves oculomotor plant compensation in simulated vestibulo-ocular reflex.. Proc Biol Sci, 269(1503), 1895-1904.
- Porrill J, Frisby JP, Adams WJ & Buckley D (1999) Robust and optimal use of information in stereo vision.. Nature, 397(6714), 63-66.
- Wilson E, Anderson SR, Prescott TJ, Dean P, Porrill J, Assaf T, Pearson MJ, Walters P, Melhuish C, Rossiter J & Pipe T (2012) Bioinspired control of electro-active polymers for next generation soft robots. Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 7429 LNAI, 424-425.